Evolution of intraflagellar transport from coated vesicles and autogenous origin of the eukaryotic cilium
Evolution of intraflagellar transport from coated vesicles and autogenous origin of the eukaryotic cilium
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DOI：
10.1002/bies.20369
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发表时间：
2006-02-01
期刊：
影响因子：
4
通讯作者：
Arendt, D
中科院分区：
文献类型：
--
作者：
Jékely, G;Arendt, D
纤毛/鞭毛是真核细胞中祖先存在的感觉运动细胞器。对于组装纤毛普遍依赖于鞭毛内运输（IFT），一个专门的双向运输过程介导的祖先和保守的IFT复合物。基于IFT复合物蛋白质的同源性的外壳蛋白I（COPI）和网格蛋白包被囊泡的组件，我们建议，非囊泡，膜结合IFT演变为一个专门的形式的包被囊泡运输从protocoatomer复杂。IFT因此与所有原衣体衍生物（包括所有囊泡外壳和核孔复合物（NPC））共享共同祖先。这对纤毛的进化起源有重大意义。首先，它加强了这样一个原则，即复制和分歧的预先存在的结构，而不是共生，是纤毛进化过程中的主要主题。其次，它表明，在自体起源的纤毛的最初步骤是建立一个膜补丁与跨膜蛋白运输的祖先囊泡涂层IFT复合物。我们提出了一个方案，最初的膜补丁如何逐渐突出，以提高暴露于环境中，然后开始移动，并最终划分，使受体信号和纤毛跳动更有效。
The cilium/flagellum is a sensory-motile organelle ancestrally present in eukaryotic cells. For assembly cilia universally rely on intraflagellar transport (IFT), a specialised bidirectional transport process mediated by the ancestral and conserved IFT complex. Based on the homology of IFT complex proteins to components of coat protein I (COPI) and clathrin-coated vesicles, we propose that the non-vesicular, membrane-bound IFT evolved as a specialised form of coated vesicle transport from a protocoatomer complex. IFT thus shares common ancestry with all protocoatomer derivatives, including all vesicle coats and the nuclear pore complex (NPC). This has major implications for the evolutionary origin of the cilium. First, it reinforces the tenet that duplication and divergence of pre-existing structures, rather than symbiosis, were the major themes during cilium evolution. Second, it suggests that the initial step in the autogenous origin of the cilium was the establishment of a membrane patch with transmembrane proteins transported by the ancestral vesicle-coating IFT complex. We propose a scenario for how the initial membrane patch gradually protruded to enhance exposure to the environment, then started to move, and finally compartmentalised to render receptor signalling and ciliary beating more efficient.